Re: [RFC net-next 1/1] hv_netvsc: Link queues to NAPIs

[Joe Damato <jdamato@fastly.com>]

On Thu, Sep 26, 2024 at 03:34:43AM -0700, Shradha Gupta wrote:
> On Wed, Sep 25, 2024 at 07:39:03PM +0000, Haiyang Zhang wrote:
> > 
> > 
> > > -----Original Message-----
> > > From: Joe Damato <jdamato@fastly.com>
> > > Sent: Tuesday, September 24, 2024 7:49 PM
> > > To: netdev@vger.kernel.org
> > > Cc: Joe Damato <jdamato@fastly.com>; KY Srinivasan <kys@microsoft.com>;
> > > Haiyang Zhang <haiyangz@microsoft.com>; Wei Liu <wei.liu@kernel.org>;
> > > Dexuan Cui <decui@microsoft.com>; David S. Miller <davem@davemloft.net>;
> > > Eric Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>;
> > > Paolo Abeni <pabeni@redhat.com>; open list:Hyper-V/Azure CORE AND DRIVERS
> > > <linux-hyperv@vger.kernel.org>; open list <linux-kernel@vger.kernel.org>
> > > Subject: [RFC net-next 1/1] hv_netvsc: Link queues to NAPIs
> > > 
> > > [You don't often get email from jdamato@fastly.com. Learn why this is
> > > important at https://aka.ms/LearnAboutSenderIdentification ]
> > > 
> > > Use netif_queue_set_napi to link queues to NAPI instances so that they
> > > can be queried with netlink.
> > > 
> > > Signed-off-by: Joe Damato <jdamato@fastly.com>
> > > ---
> > >  drivers/net/hyperv/netvsc.c       | 11 ++++++++++-
> > >  drivers/net/hyperv/rndis_filter.c |  9 +++++++--
> > >  2 files changed, 17 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
> > > index 2b6ec979a62f..ccaa4690dba0 100644
> > > --- a/drivers/net/hyperv/netvsc.c
> > > +++ b/drivers/net/hyperv/netvsc.c
> > > @@ -712,8 +712,11 @@ void netvsc_device_remove(struct hv_device *device)
> > >         for (i = 0; i < net_device->num_chn; i++) {
> > >                 /* See also vmbus_reset_channel_cb(). */
> > >                 /* only disable enabled NAPI channel */
> > > -               if (i < ndev->real_num_rx_queues)
> > > +               if (i < ndev->real_num_rx_queues) {
> > > +                       netif_queue_set_napi(ndev, i,
> > > NETDEV_QUEUE_TYPE_TX, NULL);
> > > +                       netif_queue_set_napi(ndev, i,
> > > NETDEV_QUEUE_TYPE_RX, NULL);
> > >                         napi_disable(&net_device->chan_table[i].napi);
> > > +               }
> > > 
> > >                 netif_napi_del(&net_device->chan_table[i].napi);
> > >         }
> > > @@ -1787,6 +1790,10 @@ struct netvsc_device *netvsc_device_add(struct
> > > hv_device *device,
> > >         netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
> > > 
> > >         napi_enable(&net_device->chan_table[0].napi);
> > > +       netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_RX,
> > > +                            &net_device->chan_table[0].napi);
> > > +       netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_TX,
> > > +                            &net_device->chan_table[0].napi);
> > > 
> > >         /* Connect with the NetVsp */
> > >         ret = netvsc_connect_vsp(device, net_device, device_info);
> > > @@ -1805,6 +1812,8 @@ struct netvsc_device *netvsc_device_add(struct
> > > hv_device *device,
> > > 
> > >  close:
> > >         RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
> > > +       netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_TX, NULL);
> > > +       netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_RX, NULL);
> > >         napi_disable(&net_device->chan_table[0].napi);
> > > 
> > >         /* Now, we can close the channel safely */
> > > diff --git a/drivers/net/hyperv/rndis_filter.c
> > > b/drivers/net/hyperv/rndis_filter.c
> > > index ecc2128ca9b7..c0ceeef4fcd8 100644
> > > --- a/drivers/net/hyperv/rndis_filter.c
> > > +++ b/drivers/net/hyperv/rndis_filter.c
> > > @@ -1269,10 +1269,15 @@ static void netvsc_sc_open(struct vmbus_channel
> > > *new_sc)
> > >         ret = vmbus_open(new_sc, netvsc_ring_bytes,
> > >                          netvsc_ring_bytes, NULL, 0,
> > >                          netvsc_channel_cb, nvchan);
> > > -       if (ret == 0)
> > > +       if (ret == 0) {
> > >                 napi_enable(&nvchan->napi);
> > > -       else
> > > +               netif_queue_set_napi(ndev, chn_index,
> > > NETDEV_QUEUE_TYPE_RX,
> > > +                                    &nvchan->napi);
> > > +               netif_queue_set_napi(ndev, chn_index,
> > > NETDEV_QUEUE_TYPE_TX,
> > > +                                    &nvchan->napi);
> > > +       } else {
> > >                 netdev_notice(ndev, "sub channel open failed: %d\n",
> > > ret);
> > > +       }
> > > 
> > >         if (atomic_inc_return(&nvscdev->open_chn) == nvscdev->num_chn)
> > >                 wake_up(&nvscdev->subchan_open);
> > > --
> > 
> > The code change looks fine to me.
> > @Shradha Gupta or @Erni Sri Satya Vennela, Do you have time to test this?
> > 
> > Thanks,
> > - Haiyang
> > 
> > 
> Hi Joe, Haiyang,
> 
> I have verified the patch on a VM with netvsc interfaces and the seems
> to be working as expected
> 
> CLI output after applying the patch:
> 
> [{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
>  {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
>  {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
>  {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
>  {'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'rx'},
>  {'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'rx'},
>  {'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'rx'},
>  {'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'rx'},
>  {'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'},
>  {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'tx'},
>  {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'tx'},
>  {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'tx'},
>  {'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'tx'},
>  {'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'tx'},
>  {'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'tx'},
>  {'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'tx'}]
> 
> The code changes also look good.
> 
> Tested-by: Shradha Gupta <shradhagupta@linux.microsoft.com>

Thank you very much for testing, I will include your tested-by when
I resend this next week when net-next is open.